2,2,3-Trifluoropropionyl fluoride is useful as an intermediate for the production of medicines and agricultural chemicals and as a strong acid catalyst. Further, its ester derivative is useful as a solvent, and its dehydrogenated fluorinated derivative is useful as a monomer. It is known that it can be obtained as one of many products prepared by fluorinating propionyl chloride with fluorine in the presence of a cobalt fluoride catalyst (cf. J. C. Tatlow et al, J. of Fluorine Chemistry, 1973 (3), 329-30).